Use of and process for the introduction of fibrin sealant into a puncture channel

ABSTRACT

A device for introducing a two-component fibrin sealant into a puncture channel in the vicinity of an arterial or venous puncture point, said device comprising a working cannula extending axially from an upper end to a lower end through a sealing cannula, said working cannula being used for intravascular introduction of instruments into a vessel. The working cannula is surrounded by the sealing cannula at a distance from the working cannula whereby the fibrin sealant passes from a connector at said upper end of said sealing cannula to at least one slitshaped radially directed outlet opening in said sealing cannula between said sealing cannula and said working cannula.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the use of endogenous blood coagulantsobtained from plasma protein in the form of a two-component fibrinsealant, said components being mixed at the instant they are delivered.

This invention also relates to a device for introducing thetwo-component fibrin sealant into a puncture channel in the vicinity ofan arterial or venous puncture point.

2. Description of Prior Art

Many operations in human or veterinary medicine require puncturing ofvessels. With percutaneous transluminar coronary angioplasty (PTCA),heart operations and catheterizations of the heart, in particular, it isnecessary to close the punctured vessels again with great care. In mostcases, this is performed by direct compression of up to one hour and acompression bandage which must be applied up to 24 hours and requireshospitalization of one to two days. Accordingly, there is the desire tofind a means for a more rapid and secure closure of the puncture point.

A method by the name of Vasoseal was introduced during a meeting of theAmerican Heart Association on 17 Nov. 1992 in New Orleans. In accordancewith this method, two collagen plugs made of bovine collagen are pushedinto the puncture channel as far as the puncture point. It was notedduring the meeting that, besides the somewhat rare rejection reaction ofthe exogenous collagen, there are various other disadvantages or risks.It was also noted that this system is ineffective in many cases and thatthere is a certain danger of emboli. In approximately 46% of all cases,hematomas of an order of magnitude between 2 to 6 cm were formed. Weeksor months go by before the bovine collagen is completely resorbed. Inaddition, the method leads to increased scar formation which makes anultrasonic examination more difficult. Finally, although hospitalizationdid not become superfluous, it was reduced by at least 24 hours.However, one of the most essential problems lies in the handling, thatis, the introduction of the collagen plugs into the puncture channel.Because it is necessary to push two collagen plugs successively into thepuncture channel, the user finds the penetration depth, for example,hard to determine. If the collagen plugs are pushed in too deeply, thecollagen plug may be pushed through the puncture point into the vessel,resulting in an obstruction in the vessel or the vessel itself beingpushed closed.

SUMMARY OF THE INVENTION

Accordingly, it is an object of this invention to provide a novel methodfor closing such puncture points rapidly, dependably and without theabove mentioned disadvantages.

It has been shown that when endogenous blood coagulants obtained fromplasma protein in the form of a two-component fibrin sealant, whosecomponents are mixed at the instant they are delivered, are used, andthis mixture is introduced into a puncture channel as close as possibleto a vessel during or directly following an intravascular intervention,an optimal vessel seal is created. Histological tests have proven thesefacts.

It is a further object of this invention to provide a device by whichfibrin sealant can be introduced into a puncture channel in the vicinityof an arterial or venous puncture point.

These and other objects are attained by a device in accordance with oneembodiment of this invention comprising a sealing cannula through whicha work cannula passes axially from top to bottom, wherein the workcannula which is used for the intravascular introduction of aninstrument into a vessel is surrounded at a distance by the sealingcannula, so that the fibrin sealant is conducted between the sealingcannula and the work cannula from a connector to at least one radiallyoriented outlet opening in the sealing cannula.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and objects of this invention will be betterunderstood from the following detailed description taken in conjunctionwith the drawings wherein:

FIG. 1 is a side view of the device in accordance with one embodiment ofthis invention;

FIG. 2 is a cross sectional view through the device of FIG. 1 along theline II--II on an enlarged scale;

FIG. 3 is a longitudinal cross sectional view of the device shown inFIG. 1;

FIG. 4 is an enlarged cross sectional view of the connector area of thedevice in accordance with one embodiment of this invention;

FIG. 5 is an enlarged longitudinal cross sectional view of the exit areaof the working cannula from the sealing cannula in accordance with oneembodiment of this invention;

FIG. 6 shows a side view of a second embodiment of the device of thisinvention;

FIG. 7 is a cross sectional view through the device of FIG. 6 along theline VII--VII;

FIG. 8 is a longitudinal cross sectional view through the device of FIG.6;

FIG. 9 is an enlarged cross sectional view of the connector area of thedevice shown in FIG. 8; and

FIG. 10 is a cross sectional view of the exit of the working cannulafrom the sealing cannula.

DESCRIPTION OF PREFERRED EMBODIMENTS

In what follows, two preferred embodiments of the device of thisinvention and then their manipulation and the general employment offibrin sealant for sealing a puncture point in a vessel will bedescribed. The embodiment of the device of this invention in accordancewith FIGS. 1 to 5 comprises only three elements which can be puttogether. The working cannula, also called worksheath in technicallanguage, is identified by the reference numeral 1. The working cannulaitself is a small cylindrical tube, open at both ends, made of plastic.Its front end 1' is used for introducing the cannula through thepuncture point into the opened blood vessel. The working cannula isrelatively thin-walled and therefore has a certain amount of bendingflexibility. In accordance with this embodiment of the device of thisinvention, the working cannula 1 is fixedly connected to a medicalcoupling 3 at the other end, the rear end. The actual medical coupling 3can be a known Luer locking coupling, for example. An exactly fashionedmuff 3' is formed in an interlocking and sealing manner on the actualmedical coupling 3. The working cannula 1 axially extends in thelongitudinal direction through a sealing cannula 2 and, at the frontend, projects for some distance out of the sealing cannula. The sealingcannula 2 itself is also embodied as a small concentric tube, but itsexterior diameter, and preferably also its interior diameter, decreasefrom the top end to the bottom end, that is, the interior diameter isreduced from the top end where the medical coupling 3 is inserted to thebottom end where the working cannula 1 emerges from the sealing cannula2.

Thus, a hollow space 7 is formed between the working cannula 1 and thesealing cannula 2 over the entire length where the working cannula 1 isconcentrically enclosed by the sealing cannula 2. The sealing cannula 2has a reinforced cuff 4 at the top end which has a considerably greaterwall thickness than the wall thickness of the sealing cannula 2. Aconnector 5 terminates in the sealing cannula 2 in the area of thereinforced cuff 4. A two-component fibrin sealant (F) is introduced intothe hollow space between the working cannula 1 and the sealing cannula 2through this connector 5. The fibrin sealant exits from the hollow space7 only through the at least one outlet opening 6 in the lower area ofthe sealing cannula 2. So that fibrin sealant does not unintentionallyenter the blood vessel, the at least one outlet opening 6 is at leastapproximately radially oriented toward the outside. By radially, notonly the direction, interpreted in a strictly geometric sense, is meant.Rather this is only intended to express that the outflow direction isnot axial. The functioning of the device is assured by a single outletopening, but preferably several outlet openings 6 distributed over thecircumference may be provided. Also, in principle, the form of theembodiment of the outlet openings 6 can be freely designed. However, fortechnical production reasons, they are preferably formed in the shape ofseveral linear slits distributed over the circumference.

To form an exact receptacle 15 for the medical coupling 3, the upperopening of the sealing cannula 2 must be provided with a snug fit.

For sealing the working cannula 1 against the sealing cannula 2 in thearea of the through-opening 10, an annular sealing bead or sealing rib11, which is oriented radially inward and sealingly rests on the outersurface of the working cannula 1, is disposed in the through-opening 10.

In accordance with a preferred embodiment of this invention, theconnector 5 is formed in one piece directly on the sealing cannula 2 inthe area of the reinforced cuff. It is, however, possible to manufacturethe connector separately and to connect it later with the sealingcannula by a screw connection 17. In place of the screw connection 17, awelded or adhesive connection is also possible. Mixing elements arealready available on the market for mixing the two components of thetwo-component fibrin sealant. Therefore, for reasons of cost, theconnector 5 should be sized such that an already available mixingelement 13 can be inserted into it.

As already mentioned, the wall thickness of the working cannula 1 isvery little. Preferably, it is only a few tenths of a millimeter. Thehollow space 7 remaining concentrically around the working cannula 1between its outer wall and the inner wall of the sealing cannula 2 is ofextremely small dimensions. Because all of the surgical instruments mustbe inserted and removed though the working cannula 1, it is preferred toprovide means which enable the hollow space 7 to remain continuouslyopen. Support ribs 9 which preferably extend axially are disposed on theinner wall of the sealing cannula 2 for this purpose.

The support ribs 9 also result in a stiffening of the also thin-walledsealing cannula 2. As a result, the danger is removed that a slightcontraction of the muscular tissue through which the sealing cannula 2extends could cause a deformation of the sealing cannula 2 which couldclose the hollow space 7. In this way, the required through-opening forthe fibrin sealant is assured in any case. A second preferred embodimentof the device of this invention for introducing two-component fibrinsealant through a puncture channel into the vicinity of an arterial orvenous puncture point is shown in FIGS. 6 to 10. While with the firstembodiment of this invention discussed hereinabove, the working cannula1 with the associated medical coupling 3 must be exactly adapted to thesealing cannula for a sealing connection, with this second embodiment, acommercially available working cannula with an arbitrary medicalcoupling 3 can be used. In this case, a sealing connection between themedical coupling 3 and the sealing cannula 2 not required.

Hardly any difference can be seen in the exterior shape of the twoembodiments of the devices of this invention. Accordingly, identicalparts have been given the same reference numerals in both embodiments.In accordance with the second embodiment of this invention, the workingcannula 1 completely extends in the axial direction through the sealingcannula 2. However, the medical coupling 3 fixedly disposed on theworking cannula 1 does not enter the sealing cannula 2, but is locatedshortly above it. The lower end of the working cannula 1' again isembodied as conical.

The sealing cannula 2 again has a reinforced cuff 4 at its upper end. Aconnector 5 terminates in the interior of the sealing cannula 2 in thearea of the reinforced cuff 4. At its lower end, in the area shortlyabove the through-opening 10, the sealing cannula 2 also has an outletopening 6 directed approximately radially outward. In accordance withone embodiment of this invention, several outlet openings 6 are disposedevenly distributed over the circumference, which outlet openings 6 arepreferably embodied as slits. The essential difference between thisembodiment and the previously described embodiment is seen in particularin the sectional drawing of FIG. 8. In this case, a support envelope 20is maintained in the sealing cannula 2, which defines a free space 21between itself and the inner wall of the sealing cannula 2. The workingcannula 1 passing through the sealing cannula 2 now extends inside thesupport envelope 20. The fibrin sealant pressed in through the connector5 now no longer flows directly between the outer wall of the workingcannula 1 and the inner wall of the sealing cannula 2, but insteadbetween the outer wall of the support envelope 20 and the inner wall ofthe sealing envelope 2. In the area of the lower outlet opening 10, thesealing cannula 2 is provided with a thickened head area 12. This alsoapplies to the first described embodiment. A concentric groove 23 isformed in the inside of the thickened head area 12. This groove 23narrows from top to bottom, so that the support envelope 20 is slightlywidened when it is pushed on and comes to rest sealingly in the annulargroove 23. The support envelope 20 is maintained at the top in a similarmanner in a lead-in plug 18. The lead-in plug 18 has a centeredthrough-bore 24.

The working cannula 1 enters the support envelope 20 through this bore.An annular sealing bead 25 results in a clamping and sealing support ofthe working cannula 1 in the support envelope 20. The lead-in plug 18 isprovided with a collar 25 which, in the assembled state of the lead-inplug, fits completely into a recess in the reinforced cuff 4. Thereinforced cuff 4 in accordance with one preferred embodiment isprovided with a reinforced outer diameter in the upper area to provide asufficient wall thickness. The lead-in plug 18 is also provided with anannular concentric groove 24, whose diameter widens from the bottom tothe top, so that the slightly widened support envelope 20 is heldclampingly and sealingly. As can be clearly seen from FIG. 9, thetwo-component fibrin sealant enters the free space 21 through theconnector 5 in which the mixing element 13 is disposed.

The head area 12 is preferably abruptly thickened and rounded. Theabrupt thickening is used so that the sealing cannula 2 is not pushedthrough the puncturing place in the blood vessel into the latter. On theother hand, the rounding is intended to ease the introduction of thesealing cannula 2 into the puncture channel.

The working cannula 1 is here also sealed against the sealing cannula 2.This is achieved by a sealing lip 22 at the end, which rests on theouter wall of the working cannula 1.

However, the function of the annular sealing lip 22 in accordance withthis embodiment is not the same as that of the sealing bead 11 or thesealing ring of the first embodiment described hereinabove, namely forsealing the hollow space of the sealing envelope 2 and thus preventingthe exit of the fibrin sealant in the axial direction, but rather isused for preventing the entry of blood into the area between the workingcannula 1 and the support envelope 20.

The employment of the device in accordance with this invention will bebriefly described. In a first step, in the course of catheterization, ahollow needle is pushed through the skin and the various tissue layersunderneath it up to the blood vessel to be punctured. A guide is pushedinto the blood vessel through the hollow needle. Leaving the guide inthe introduced position, the hollow needle is retracted over the guideand in place of it a dilator is pushed through the puncture channel intothe blood vessel. Afterwards, the working cannula 1 and the sealingcannula 2 are then fed through the dilator, wherein the working cannula1 is inserted into the blood vessel, while the abruptly thickened headarea of the sealing cannula 2 is only pushed in as far as the puncturepoint. Thus the outlet openings 6 are located above the puncture pointof the blood vessel, but inside the puncture channel. The physician nowinserts the necessary instruments through the working cannula 1 into theblood vessel. This may be a balloon catheter, a fiber-optical wave guideor the probe of a camera or also other means.

At the end of the operation or examination, first the instruments arepulled out of the vessel through the working cannula 1 and then thetwo-component fibrin sealant is pressed through the connector 5, thefree space 21 or the hollow space 7 and through the outlet openings 6into the puncture channel. After only a few seconds, the fibrin sealantresults in coagulation into a fibrin clot of the blood in the area ofthe puncture channel or the puncture point, as a result of whichbleeding is completely stopped. The formation of hematomas is entirelyprevented. A risk of an embolus could no longer be noted. A one hundredpercent effectiveness has been achieved in all tests performed to date.No rejection reactions to the human fibrin sealant were noted. Even withthe use of an increased concentration of aprotinin, excellent sealingwas obtained in animal tests.

Hospitalization of the patient can therefore be omitted.

The use of the human two-component fibrin sealant, known for severalyears, for use in sealing a puncture point or a puncture channel to thepuncture point is not known. This novel sealing method by a fibrinsealant is in no way obvious, because up to now it has always beenassumed that the entry of fibrin sealant into the bloodstream could leadto complications. Only the present applicator permits a danger-free useof the fibrin sealant.

The application, in accordance with this invention, of the fibrinsealant can also be done without the device of this invention in thatthe fibrin sealant is directly applied in the puncture channel by aninjection needle. However, because the exact location of the puncturechannel by an injection needle is not simple, it is preferred not toemploy this method. If the injection of the fibrin sealant takes placeoutside the area of the puncture channel, there will of course be nosealing of the blood vessel.

Surely other embodiments, besides the above described preferredembodiments of the device in accordance with this invention, areconceivable without departing from the basic concept of this invention.

I claim:
 1. In a device for introducing a two-component fibrin sealantinto a puncture channel in the vicinity of an arterial or venouspuncture point, said device comprising a sealing cannula (2), throughwhich a working cannula, having an open distal end and a proximal endwith a fixedly connected medical coupling, extends axially from an upperend through a lower end of said sealing cannula (2), said workingcannula movable within said sealing cannula (2) and suitable forconveying intravascular instruments through said working cannula into avessel, the improvement comprising: the working cannula (1) surroundedat a distance by the sealing cannula (2), whereby the fibrin sealant isconveyed from a connector (5) connected to said upper end of saidsealing cannula (2) to at least one slit-shaped radially directed outletopening (6) in the sealing cannula (2) between the sealing cannula (2)and the working cannula (1); and said sealing cannula (2) comprising areinforced cuff (4) formed as one piece on an upper end of said sealingcannula (2), an inner diameter of said sealing cannula (2) being reducedfrom an area of the termination of the connector (5) to the at least oneslit-shaped radially directed outlet opening (6).
 2. In a device inaccordance with claim 1, wherein the connector (5) is laterallyintegrally formed on the reinforced cuff (4).
 3. In a device inaccordance with claim 3, wherein a mixing element (13) is insertablymaintained in the connector (5).
 4. In a device in accordance with claim1, wherein the connector (5) is a separate piece and is connected to thereinforced cuff (17).
 5. In a device in accordance with claim 1, whereinthe sealing cannula (2) comprises at least one inwardly oriented supportrib (9), thereby maintaining a hollow space (7) for conducting thefibrin sealant (F) from the connector (5) to the at least one outletopening (6).
 6. In a device in accordance with claim 7, wherein the atleast one support rib (9) is arranged to extend at least approximatelyradially.
 7. In a device in accordance with claim 1, wherein the workingcannula (1) is fixedly connected to a medical coupling (3), said medicalcoupling (3)maintained in the reinforced cuff (4) of the sealing cannula(2) in one of a frictionally and interlockingly sealing manner andextending axially in respect to the working cannula (1).
 8. In a devicein accordance with claim 7, wherein in the area of a lower passage (10)of the working cannula (1) through the sealing cannula (2), the sealingcannula (2) comprises a radially inward directed annular sealing bead(11).
 9. In a device in accordance with claim 1, wherein the sealingcannula (2) is closed at said upper end by a lead-in plug (18), atube-shaped support envelope (20) is sealingly maintained within saidlead-in plug (18), said robe-shaped support envelope (20) extendingthrough the sealing cannula (2) and sealingly maintained at the oppositelower end in the sealing cannula (2), said working cannula (1) freelymovable in the support envelope (20), whereby the fibrin sealant (F) canflow in a radial free space (21) formed between the supporting envelope(20) and the sealing cannula (2) from the connector (5) to said at leastone outlet opening (6).
 10. In a device in accordance with claim 9,wherein the support envelope (20) comprises a plurality of stiffeningribs (16) directed radially outward and toward an inner wall of thesealing cannula (2).
 11. In a device in accordance with claim 1, whereinthe sealing cannula (2) comprises an abruptly widened rounded head area(12) at the lower end where the working cannula (1) emerges from thesealing cannula (2).
 12. A device in accordance with claim 11, whereinthe head area (12) comprises an axially extending annular sealing lip(22) seated on the working cannula (1).